Trial of Fairford Five will put pressure on Goldsmith

The attorney general, Lord Goldsmith, will come under new pressure to disclose his full advice on the legality of the Iraq war in the run-up to a five-day hearing by a high court judge in April.

Five peace activists charged with criminal damage at RAF Fairford are pleading – like Katharine Gun, the former GCHQ translator whose prosecution under the Official Secrets Act for leaking a memo was thrown out last week – that they acted to prevent an illegal war.

If Mr Justice Grigson agrees that they can invoke the two defences of necessity and prevention of crime, Tony Blair could face the embarrassing prospect of an ordinary jury of 12 citizens deciding whether or not the defendants had reasonable grounds for believing that the war was legal under international law. The prosecution has retained Christopher Greenwood QC, professor of law at LSE and the expert whose advice Lord Goldsmith relied on in reaching the view that that the war was lawful, to argue the international law aspects of the case.

The Guardian understands that Lord Goldsmith’s original advice was more equivocal than the opinion which was ultimately made public.

Last March, a few days before the war started, Paul Milling and Margaret Jones cut their way into Fairford air force base. They disabled trucks used for carrying bombs, and tankers for fuelling the US B-52 bombers waiting to attack Iraq, causing tens of thousands of pounds of damage.

Later Phil Pritchard, Toby Olditch and Josh Richards were arrested inside Fairford while trying to reach and disarm a B-52.

At Bristol crown court from April 26, Mr Justice Grigson will hear arguments on whether the five activists are entitled to put forward the defences of necessity and prevention of crime.

A QC unconnected with the case said the events of the past two days, since the Gun case collapsed, had been “extremely helpful” to the Fairford Five. He said the only possible interpretation of the attorney general’s statement that the prosecution had concluded in the Gun case that it could not rebut the defence of necessity was that “in all the uncertainty surrounding the legality of the war in Iraq, it was impossible to prove Ms Gun did not reasonably believe she was acting to prevent an illegal war”.

Hugo Charlton, a barrister representing Dr Jones and Mr Richards, said the defendants in the case would be seeking disclosure of the attorney general’s original advice.